The present invention relates to a developing apparatus and a developing nozzle used in the manufacture of a semiconductor device or a liquid crystal display (LCD) device, particularly, to a developing apparatus and a developing nozzle for development of a chemically amplified resist film in photolithography of a semiconductor device.
In a manufacturing process of a semiconductor device, a semiconductor wafer is coated with resist, and the coated resist film is baked, exposed to light and, then, developed. Used in such treatments are a coating-developing system disclosed in, for example, U.S. Pat. No. 5,664,254 and U.S. Pat. No. 5,700,127. The coating-developing system, which is used in combination with a light exposure apparatus in a photolithography for a semiconductor device, includes a resist coating unit and a developing unit.
In the developing unit, a wafer having a resist film formed thereon, said resist film bearing a light-exposed latent image, is held by a spin chuck, and a nozzle extending over the diameter of the wafer is positioned right above the wafer. Under this condition, the wafer is rotated to make at least half the complete rotation while supplying a developing solution from the discharge port of the nozzle onto the wafer. As a result, a film of the developing solution is formed in a uniform thickness over the entire upper surface of the wafer. The wafer having the film of the developing solution formed thereon is held stationary for a predetermined time to have the developing solution kept in contact with the resist film formed on the wafer so as to develop the light-exposed latent image formed in the resist film. The particular developing method is called a puddle development.
In the puddle development, it is desirable to make the total residence time (total contact time) of the developing solution uniform over the entire surface of the wafer in order to ensure uniformity of the line width of the circuit. Therefore, it is necessary to coat the entire surface of the wafer with the developing solution as promptly as possible and, thus, the developing solution is supplied from the supply source to the nozzle at a high pressure.
However, since the discharge port of the nozzle has a small diameter, a high supply pressure of the developing solution imparts an excessively large impact to the light-exposed latent image formed in the resist film, leading to nonuniformity in the line width. Particularly, since the line width of the pattern formed in a chemically amplified resist film is on the submicron order, a serious influence tends to be imparted to the light-exposed latent image formed in the resist film, if the developing solution discharged from the nozzle has a large colliding force.
It should also be noted that the developing nozzle is made of a resin having a high water repellency. Therefore, if the developing solution is discharged at a high speed, the discharge range of the developing solution tends to be narrowed when the developing solution is discharged from the discharge port, with the result that the developing solution tends to fail to be supplied to the entire region of the wafer so as to bring about undeveloped portions. The tendency is particularly prominent in the case of the scanning system in which the developing solution is discharged while the nozzle is moved along the wafer surface.